Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It works by sampling the amplitude of the analog signal at regular intervals and converting these samples into a series of binary numbers. This process allows for the accurate reproduction of the original signal when it is played back. PCM is widely used in various applications, including audio recording, telecommunications, and video transmission. By converting sound waves into digital data, PCM enables high-quality audio playback and efficient transmission over different media, making it a fundamental technology in modern digital communication systems.